package cn.stylefeng.guns.modular.util;

import org.apache.commons.codec.digest.DigestUtils;

import java.io.UnsupportedEncodingException;
import java.security.MessageDigest;

public class MD5Util {

    /**
     * 功能描述:字符串转换为MD5
     *
     * @param str 字符串
     * @return
     * @author houkun  2013-7-18 上午08:52:29
     */
    public static String encoderByMd5(String str) {
        if (str == null || "".equals(str)) {
            return "";
        }
        byte[] unencodedPassword = str.getBytes();
        MessageDigest md = null;
        try {
            md = MessageDigest.getInstance("MD5");
        } catch (Exception e) {
            return str;
        }
        md.reset();
        md.update(unencodedPassword);
        byte[] encodedPassword = md.digest();
        StringBuffer buf = new StringBuffer();
        for (int i = 0; i < encodedPassword.length; i++) {
            if ((encodedPassword[i] & 0xff) < 0x10) {
                buf.append("0");
            }
            buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
        }
        return buf.toString();
    }


    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname)) {
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));
            } else {
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetname)));
            }
        } catch (Exception exception) {
        }
        return resultString;
    }

    public static String MD5Encode_1(String origin) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            resultString = byteArrayToHexString(md.digest(resultString
                    .getBytes()));
        } catch (Exception ex) {
        }
        return resultString;
    }

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};




    //<editor-fold desc="copy">
    public static String encryptMd5(String string) throws UnsupportedEncodingException {
        return encryptMd5(string, "UTF-8");
    }

    public static String encryptMd5(String string, String charSet) throws UnsupportedEncodingException {
        return DigestUtils.md5Hex(string.getBytes(charSet));
    }
    //</editor-fold>



}
